A great variety of displays are used to exhibit advertising on the sides of moving vehicles such as vans, buses or tractor trailers. The displays typically are fabricated by painting the advertisement directly on the surface of the vehicle, or by applying sign panels to the surface using adhesives or by applying an adhesive film containing an advertisement. These displays are expensive, difficult to install, and difficult to change in timely fashion. In addition, their useful life is limited by constant exposure to the elements even when not in use. Rigid signs or signs with protective enclosures are easier to change and more impervious to the elements, but are cumbersome and limited in size and can often be prohibitively heavy.
A number of improved displays using tensioned panels have been proposed which are adapted to use on mobile surfaces. These systems offer the ability to change the display in a more timely and efficient manner, while the ability to roll up the panel for easy storage or transport helps reduce environmental wear and prolong the display's useful life. However, complex and costly tensioning frames are typically required in order to tension the fabric panel. For example, U.S. Pat. No. 4,580,361 discloses a tensioning frame which employs edge rails with integral spring tensioners to apply tension to the periphery of an advertising panel. Besides being complex and prone to mechanical failure after prolonged environmental exposure, these edge rails protrude significantly from the mounting surface and may be unusable in some tractor trailer applications because of width restrictions.
U.S. Pat. No. 5,239,765 discloses another type of tensioned panel display which uses an elastic panel tensioned between top and bottom stays which are held in place by two rows of anchors. While this offers an improvement over the more complex mounting frame described above, it suffers from several disadvantages arising from the use of an elastic panel in a rigid mounting. It requires a complex mounting procedure and extensive adjustments in order to achieve and maintain the proper tensioning of the panel. Multiple anchors must be aligned to achieve uniform tension across the panel and minimize wrinkling and flutter. Stretching due to the frame flex inherent in large trailers necessitates frequent readjustment of the stays and anchors. A further disadvantage is that there is nothing, beyond the tension on the panel itself, to prevent the impinging air stream from getting under the leading edge of the panel, causing flutter, damage or dislocation.
It would be advantageous if a mobile advertising display using a tensioned panel could be devised which provides for quick and easy installation, has an easily adjustable tensioning means which compensates for flexure of the structure on which the display is mounted, and has a sealed leading edge which prevents the display from being undermined by an impinging airstream.